Tyrosine kinase inhibition: an approach to drug development

Satellite glial cell manipulation prior to axotomy enhances developing dorsal root ganglion central branch regrowth into the spinal cord

The central and peripheral nervous systems (CNS and PNS, respectively) exhibit remarkable diversity in the capacity to regenerate following neuronal injury with PNS injuries being much more likely to regenerate than those that occur in the CNS. Glial responses to damage greatly influence the likelihood of regeneration by either promoting or inhibiting axonal regrowth over time. However, despite our understanding of how some glial lineages participate in nerve degeneration and regeneration, less is known about the contributions of peripheral satellite glial cells (SGC) to regeneration failure following central axon branch injury of dorsal root ganglia (DRG) sensory neurons. Here, using in vivo, time-lapse imaging in larval zebrafish coupled with laser axotomy, we investigate the role of SGCs in axonal regeneration. In our studies we show that SGCs respond to injury by relocating their nuclei to the injury site during the same period that DRG neurons produce new central branch neurites. Laser ablation of SGCs prior to axon injury results in more neurite growth attempts and ultimately a higher rate of successful central axon regrowth, implicating SGCs as inhibitors of regeneration. We also demonstrate that this SGC response is mediated in part by ErbB signaling, as chemical inhibition of this receptor results in reduced SGC motility and enhanced central axon regrowth. These findings provide new insights into SGC-neuron interactions under injury conditions and how these interactions influence nervous system repair.

Green synthesis, in silico modeling, and biological evaluation of N-substituted (Z)-5-arylidene imidazolidine/thiazolidine-2,4-dione/4-thione derivatives catalyzed by Bu SO3H core-shell nanostructures

In this effort, the immobilization of guanidine-sulfonate on the surface of Fe3O4 MNPs (magnetic nanoparticles) as a novel acid nanocatalyst has been successfully reported for the synthesis of N-substituted (Z)-5-arylidene thiazolidine-2,4-dione and related cyclic derivatives, including rhodanine (RHD) and hydantoin (HYD) via a one-pot multiple-component reaction under green conditions. The products were characterized by SEM, TEM, TGA, EDS, BET techniques, VSM, and FTIR. The novel compounds synthesized using this methodology, designated as series La (1-9), Lb (1-8), and Lc (1-8), were subjected to anticancer screening against A549 and MCF7cell lines via MTT assays. Notably, several compounds (L1a, L2a, L3a, L1b, L2b, L3b, and L4b) exhibited potent antiproliferative activities, with observed IC50 values as low as 1.23 μM and 1.02 μM against MCF-7 cells, thereby outperforming the established anticancer drugs doxorubicin and cisplatin. Molecular docking and dynamics simulations revealed that ligands L1a, L2a, and L3a strongly interact with the protein target 3CD8, with L1a displaying significant hydrophobic and hydrogen bonding interactions and L2a engaging in unique pi-pi stacking with key residues. For protein 2WGJ, ligand L4b exhibited exceptional binding affinity, characterized by robust hydrogen bonding, hydrophobic interactions, and additional stabilizing mechanisms such as water bridges and pi interactions. Hence, N-substituted (Z)-5-arylidene thiazolidine-2,4-dione and its cyclic derivatives may serve as promising candidates for further exploration in the development of new multi-target cancer chemotherapy agents. These findings introduce promising anticancer agents and establish Fe3O4 MNPs as a versatile and environmentally sustainable catalytic platform in drug discovery.

Phosphorylated protein chip combined with artificial intelligence tools for precise drug screening

We have developed a protein array system, named "Phospho-Totum", which reproduces the phosphorylation state of a sample on the array. The protein array contains 1471 proteins from 273 known signaling pathways. According to the activation degrees of tyrosine kinases in the sample, the corresponding groups of substrate proteins on the array are phosphorylated under the same conditions. In addition to measuring the phosphorylation levels of the 1471 substrates, we have developed and performed the artificial intelligence-assisted tools to further characterize the phosphorylation state and estimate pathway activation, tyrosine kinase activation, and a list of kinase inhibitors that produce phosphorylation states similar to that of the sample. The Phospho-Totum system, which seamlessly links and interrogates the measurements and analyses, has the potential to not only elucidate pathophysiological mechanisms in diseases by reproducing the phosphorylation state of samples, but also be useful for drug discovery, particularly for screening targeted kinases for potential drug kinase inhibitors.

Data-oriented protein kinase drug discovery

The continued growth of data from biological screening and medicinal chemistry provides opportunities for data-driven experimental design and decision making in early-phase drug discovery. Approaches adopted from data science help to integrate internal and public domain data and extract knowledge from historical in-house data. Protein kinase (PK) drug discovery is an exemplary area where large amounts of data are accumulating, providing a valuable knowledge base for discovery projects. Herein, the evolution of PK drug discovery and development of small molecular PK inhibitors (PKIs) is reviewed, highlighting milestone developments in the field and discussing exemplary studies providing a basis for increasing data orientation of PK discovery efforts.

The potential of phytochemicals against epidermal growth factor receptor tyrosine kinase (EGFRK): an insight from molecular dynamic simulations

Cancer is an umbrella term used to define various diseases with abnormal cell proliferation at the focal point. According to the WHO, cancer is the leading cause of death worldwide, with lung cancer being the second most common perpetrator after breast cancer. There are several proteins acting in harmony that lead to cancer. EGFR has been identified as one of the proteins that is linked to cell division, even when it is cancerous in nature. Cancer can be treated using therapeutic agents that target EGFR or their signaling networks. Available drugs that could inhibit EGFR have acquired resistance in most cases and multiple side effects on the human body. That is why phytochemicals are being studied for their role in this case. Around 8000 compounds were retrieved from our previously created phytochemdb database for their drug activity, and the 3D protein structure was collected from the protein data bank. The selected dataset of ligands was virtually screened through HTVS, SP, and XP to retain the top 4 hits. Molecular dynamics revealed the stability and flexibility of protein-(selected)ligand interactions. The non-bond interactions of each of the compounds with EGFR, such as Gossypetin interacting with active site MET769 and ASP831; Muxiangrine III interacting with MET769 and ASP831; Quercetagetin showing non-bonded interactions with GLU738, GLN767, and MET769 for >100% of the simulation timeframe These findings suggest further research into these compounds, which can yield a potential phytochemical drug against cancer.Communicated by Ramaswamy H. Sarma.

Comprehensive Data-Driven Assessment of Non-Kinase Targets of Inhibitors of the Human Kinome

Protein kinases (PKs) are involved in many intracellular signal transduction pathways through phosphorylation cascades and have become intensely investigated pharmaceutical targets over the past two decades. Inhibition of PKs using small-molecular inhibitors is a premier strategy for the treatment of diseases in different therapeutic areas that are caused by uncontrolled PK-mediated phosphorylation and aberrant signaling. Most PK inhibitors (PKIs) are directed against the ATP cofactor binding site that is largely conserved across the human kinome comprising 518 wild-type PKs (and many mutant forms). Hence, these PKIs often have varying degrees of multi-PK activity (promiscuity) that is also influenced by factors such as single-site mutations in the cofactor binding region, compound binding kinetics, and residence times. The promiscuity of PKIs is often-but not always-critically important for therapeutic efficacy through polypharmacology. Various in vitro and in vivo studies have also indicated that PKIs have the potential of interacting with additional targets other than PKs, and different secondary cellular targets of individual PKIs have been identified on a case-by-case basis. Given the strong interest in PKs as drug targets, a wealth of PKIs from medicinal chemistry and their activity data from many assays and biological screens have become publicly available over the years. On the basis of these data, for the first time, we conducted a systematic search for non-PK targets of PKIs across the human kinome. Starting from a pool of more than 155,000 curated human PKIs, our large-scale analysis confirmed secondary targets from diverse protein classes for 447 PKIs on the basis of high-confidence activity data. These PKIs were active against 390 human PKs, covering all kinase groups of the kinome and 210 non-PK targets, which included other popular pharmaceutical targets as well as currently unclassified proteins. The target distribution and promiscuity of the 447 PKIs were determined, and different interaction profiles with PK and non-PK targets were identified. As a part of our study, the collection of PKIs with activity against non-PK targets and the associated information are made freely available.

Transforming Growth Factor α Evokes Aromatase Expression in Gastric Parietal Cells during Rat Postnatal Development

Estrogen, well known as a female hormone, is synthesized primarily by ovarian aromatase. However, extra-glandular tissues also express aromatase and produce estrogen. It is noteworthy that aromatase in gastric parietal cells begins expression around 20 days after birth and continues secreting considerable amounts of estrogen into the portal vein throughout life, supplying it to the liver. Estrogen, which is secreted from the stomach, is speculated to play a monitoring role in blood triglyceride, and its importance is expected to increase. Nevertheless, the regulatory mechanisms of the aromatase expression remain unclear. This study investigated the influence of transforming growth factor α (TGFα) on gastric aromatase expression during postnatal development. The administration of TGFα (50 μg/kg BW) to male Wistar rats in the weaning period resulted in enhanced aromatase expression and increased phosphorylated ERK1+2 in the gastric mucosa. By contrast, administration of AG1478 (5 mg/kg BW), a protein tyrosine kinase inhibitor with high selectivity for the epidermal growth factor receptor and acting as an antagonist of TGFα, led to the suppression of aromatase expression. In fact, TGFα expression in the gastric fundic gland isthmus began around 20 days after birth in normal rats as did that of aromatase, which indicates that TGFα might induce the expression of aromatase in the parietal cells concomitantly.

A biophysical approach of tyrphostin AG879 binding information in: bovine serum albumin, human ErbB2, c-RAF1 kinase, SARS-CoV-2 main protease and angiotensin-converting enzyme 2

Viral infections cause significant health problems all over the world, and it is critical to develop treatments for these problems. Antivirals that target viral genome-encoded proteins frequently cause the virus to become more resistant to treatment. Because viruses rely on several cellular proteins and phosphorylation processes that are essential to their life cycle, drugs targeting host-based targets could be a viable treatment option. To reduce costs and improve efficiency, existing kinase inhibitors could be repurposed as antiviral medications; however, this method rarely works, and specific biophysical approaches are required in the field. Because of the widespread use of FDA-approved kinase inhibitors, it is now possible to better understand how host kinases contribute to viral infection. The purpose of this article is to investigate the tyrphostin AG879 (Tyrosine kinase inhibitor) binding information in Bovine Serum Albumin (BSA), human ErbB2 (HER2), C-RAF1 Kinase (c-RAF), SARS-CoV-2 main protease (COVID 19), and Angiotensin-converting enzyme 2 (ACE-2).Communicated by Ramaswamy H. Sarma.

Precision Deuteration in Search of Anticancer Agents: Approaches to Cancer Drug Discovery

Cancer chemotherapy has been shifted from conventional cytotoxic drug therapy to selective and target-specific therapy after the findings about DNA changes and proteins that are responsible for cancer. A large number of newer drugs were discovered as targeted therapy for particular types of neoplastic disease. The initial discovery includes the development of the first in the category, imatinib, a Bcr-Abl tyrosine kinase inhibitor (TKI) for the treatment of chronic myelocytic leukemia in 2001. But the joy did not last for long as the drug developed a point mutation within the ABL1 kinase domain of BCR-ABL1, which subsequently led to the discovery of many other TKIs. Resistance was observed for newer TKIs a few years after their launching, but the use of TKIs in life-threatening cancer therapy is considered as far better compared with the risks of disease because of its target specificity and hence less toxicity. In search of a better anticancer agent, the physiochemical properties of the lead molecule have been modified for its efficacy toward disease and delay in the development of resistance. Deuteration in the drug molecule is one of such modifications that alter the pharmacokinetic properties, generally its metabolism, as compared with its pharmacodynamic effects. Precision deuteration in many anticancer drugs has been carried out to search for better drugs for cancer. In this review, the majority of anticancer drugs and molecules for which deuteration was applied to get better anticancer molecules were discussed. This review will provide a complete guide about the benefits of deuteration in cancer chemotherapy.

An essential signaling cascade for avian auditory hair cell regeneration

Hearing loss is a chronic disease affecting millions of people worldwide, yet no restorative treatment options are available. Although non-mammalian species can regenerate their auditory sensory hair cells, mammals cannot. Birds retain facultative stem cells known as supporting cells that engage in proliferative regeneration when surrounding hair cells die. Here, we investigated gene expression changes in chicken supporting cells during auditory hair cell death. This identified a pathway involving the receptor F2RL1, HBEGF, EGFR, and ERK signaling. We propose a cascade starting with the proteolytic activation of F2RL1, followed by matrix-metalloprotease-mediated HBEGF shedding, and culminating in EGFR-mediated ERK signaling. Each component of this cascade is essential for supporting cell S-phase entry in vivo and is integral for hair cell regeneration. Furthermore, STAT3-phosphorylation converges with this signaling toward upregulation of transcription factors ATF3, FOSL2, and CREM. Our findings could provide a basis for designing treatments for hearing and balance disorders.

Apical extrusion prevents apoptosis from activating an acute inflammatory program in epithelia

Apoptosis is traditionally considered to be an immunologically silent form of cell death. Multiple mechanisms exist to ensure that apoptosis does not stimulate the immune system to cause inflammation or autoimmunity. Against this expectation, we now report that epithelia are programmed to provoke, rather than suppress, inflammation in response to apoptosis. We found that an acute inflammatory response led by neutrophils occurs in zebrafish and cell culture when apoptotic epithelial cells cannot be expelled from the monolayer by apical extrusion. This reflects an intrinsic circuit where ATP released from apoptotic cells stimulates epithelial cells in the immediate vicinity to produce interleukin-8 (IL-8). Apical extrusion therefore prevents inappropriate epithelial inflammation by physically eliminating apoptotic cells before they can activate this pro-inflammatory circuit. This carries the implication that epithelia may be predisposed to inflammation, elicited by sporadic or induced apoptosis, if apical extrusion is compromised.

Anticancer pan-ErbB inhibitors reduce inflammation and tissue injury and exert broad-spectrum antiviral effects

Targeting host factors exploited by multiple viruses could offer broad-spectrum solutions for pandemic preparedness. Seventeen candidates targeting diverse functions emerged in a screen of 4,413 compounds for SARS-CoV-2 inhibitors. We demonstrated that lapatinib and other approved inhibitors of the ErbB family of receptor tyrosine kinases suppress replication of SARS-CoV-2, Venezuelan equine encephalitis virus (VEEV), and other emerging viruses with a high barrier to resistance. Lapatinib suppressed SARS-CoV-2 entry and later stages of the viral life cycle and showed synergistic effect with the direct-acting antiviral nirmatrelvir. We discovered that ErbB1, ErbB2, and ErbB4 bind SARS-CoV-2 S1 protein and regulate viral and ACE2 internalization, and they are required for VEEV infection. In human lung organoids, lapatinib protected from SARS-CoV-2-induced activation of ErbB-regulated pathways implicated in non-infectious lung injury, proinflammatory cytokine production, and epithelial barrier injury. Lapatinib suppressed VEEV replication, cytokine production, and disruption of blood-brain barrier integrity in microfluidics-based human neurovascular units, and reduced mortality in a lethal infection murine model. We validated lapatinib-mediated inhibition of ErbB activity as an important mechanism of antiviral action. These findings reveal regulation of viral replication, inflammation, and tissue injury via ErbBs and establish a proof of principle for a repurposed, ErbB-targeted approach to combat emerging viruses.

Free-Fatty Acid Receptor-4 (FFA4/GPR120) differentially regulates migration, invasion, proliferation and tumor growth of papillary renal cell carcinoma cells

Kidney cancer is among the 10 most common cancers, and renal cell carcinoma (RCC), which represent 90% of all kidney cancers, has the highest mortality rate of all genitourinary cancers. Papillary RCC (pRCC) is the second most frequent subtype of RCC and demonstrates distinct characteristics compared to other subtypes, including a high degree of metastasis and resistance to treatments against the more common clear cell RCC (ccRCC) subtype. Here, we demonstrate that the Free-Fatty Acid Receptor-4 (FFA4), a G protein-coupled receptor that is endogenously activated by medium-to-long chain free-fatty acids, is upregulated in pRCC compared to patient-matched normal kidney tissue, and that the expression of FFA4 increases with the degree of pathological grading of pRCC. Our data also show that FFA4 transcript is not expressed in ccRCC cell lines, but is expressed in the well-characterized metastatic pRCC cell line ACHN. Furthermore, we show that agonism of FFA4 with the selective agonist cpdA positively regulates ACHN cell migration and invasion in a manner dependent on PI3K/AKT/NF-κB signaling to COX-2 and MMP-9, with partial-dependence on EGFR transactivation. Our results also demonstrate that FFA4 agonism induces STAT-3-driven epithelial-mesenchymal transition, suggesting a significant role for FFA4 in pRCC metastasis. On the contrary, FFA4 agonism significantly reduces cell proliferation and tumor growth, suggesting that the receptor may have opposing effects on pRCC cell growth and migration. Together, our data demonstrate that FFA4 has significant functional roles in pRCC cells and may be an attractive target for study of pRCC and development of RCC pharmacotherapeutics.

Free-fatty acid receptor-1 (FFA1/GPR40) promotes papillary RCC proliferation and tumor growth via Src/PI3K/AKT/NF-κB but suppresses migration by inhibition of EGFR, ERK1/2, STAT3 and EMT

BACKGROUND

Papillary renal cell carcinoma (pRCC) is a highly metastatic genitourinary cancer and is generally irresponsive to common treatments used for the more prevalent clear-cell (ccRCC) subtype. The goal of this study was to examine the novel role of the free fatty-acid receptor-1 (FFA1/GPR40), a cell-surface expressed G protein-coupled receptor that is activated by medium-to-long chained dietary fats, in modulation of pRCC cell migration invasion, proliferation and tumor growth.

METHODS

We assessed the expression of FFA1 in human pRCC and ccRCC tumor tissues compared to patient-matched non-cancerous controls, as well as in RCC cell lines. Using the selective FFA1 agonist AS2034178 and the selective FFA1 antagonist GW1100, we examined the role of FFA1 in modulating cell migration, invasion, proliferation and tumor growth and assessed the FFA1-associated intracellular signaling mechanisms via immunoblotting.

RESULTS

We reveal for the first time that FFA1 is upregulated in pRCC tissue compared to patient-matched non-cancerous adjacent tissue and that its expression increases with pRCC cancer pathology, while the inverse is seen in ccRCC tissue. We also show that FFA1 is expressed in the pRCC cell line ACHN, but not in ccRCC cell lines, suggesting a unique role in pRCC pathology. Our results demonstrate that FFA1 agonism promotes tumor growth and cell proliferation via c-Src/PI3K/AKT/NF-κB and COX-2 signaling. At the same time, agonism of FFA1 strongly inhibits migration and invasion, which are mechanistically mediated via inhibition of EGFR, ERK1/2 and regulators of epithelial-mesenchymal transition.

CONCLUSIONS

Our data suggest that FFA1 plays oppositional growth and migratory roles in pRCC and identifies this receptor as a potential target for modulation of pathogenesis of this aggressive cancer.

Anticancer pan-ErbB inhibitors reduce inflammation and tissue injury and exert broad-spectrum antiviral effects

Targeting host factors exploited by multiple viruses could offer broad-spectrum solutions for pandemic preparedness. Seventeen candidates targeting diverse functions emerged in a screen of 4,413 compounds for SARS-CoV-2 inhibitors. We demonstrated that lapatinib and other approved inhibitors of the ErbB family receptor tyrosine kinases suppress replication of SARS-CoV-2, Venezuelan equine encephalitis virus (VEEV), and other emerging viruses with a high barrier to resistance. Lapatinib suppressed SARS-CoV-2 entry and later stages of the viral life cycle and showed synergistic effect with the direct-acting antiviral nirmatrelvir. We discovered that ErbB1, 2 and 4 bind SARS-CoV-2 S1 protein and regulate viral and ACE2 internalization, and they are required for VEEV infection. In human lung organoids, lapatinib protected from SARS-CoV-2-induced activation of ErbB-regulated pathways implicated in non-infectious lung injury, pro-inflammatory cytokine production, and epithelial barrier injury. Lapatinib suppressed VEEV replication, cytokine production and disruption of the blood-brain barrier integrity in microfluidic-based human neurovascular units, and reduced mortality in a lethal infection murine model. We validated lapatinib-mediated inhibition of ErbB activity as an important mechanism of antiviral action. These findings reveal regulation of viral replication, inflammation, and tissue injury via ErbBs and establish a proof-of-principle for a repurposed, ErbB-targeted approach to combat emerging viruses.

Golgi-Targeting Anticancer Natural Products

The Golgi apparatus plays an important role in maintaining cell homeostasis by serving as a biosynthetic center for glycans, lipids and post-translationally modified proteins and as a sorting center for vesicular transport of proteins to specific destinations. Moreover, it provides a signaling hub that facilitates not only membrane trafficking processes but also cellular response pathways to various types of stresses. Altered signaling at the Golgi apparatus has emerged as a key regulator of tumor growth and survival. Among the small molecules that can specifically perturb or modulate Golgi proteins and organization, natural products with anticancer property have been identified as powerful chemical probes in deciphering Golgi-related pathways and, in particular, recently described Golgi stress response pathways. In this review, we highlight a set of Golgi-targeting natural products that enabled the characterization of the Golgi-mediated signaling events leading to cancer cell death and discuss the potential for selectively exploiting these pathways for the development of novel chemotherapeutic agents.

Dietary Diindolylmethane Enhances the Therapeutic Effect of Centchroman in Breast Cancer by Inhibiting Neoangiogenesis

Tumor angiogenesis is primarily regulated by vascular endothelial growth factor and its receptor (VEGF-VEGFR) communication, which is involved in cancer cell growth, progression, and metastasis. Diindolylmethane (DIM), a dietary bioactive from cruciferous vegetables, has been extensively studied in preclinical models for breast cancer prevention and treatment. Nevertheless, the possible role of DIM in the angiogenesis and metastasis regulations in triple-negative breast cancer (TNBC) remains elusive. Here, we investigated the potential anti-angiogenic and anti-metastatic role of DIM in combination with centchroman (CC). We observed that the oral administration of the DIM and CC combination suppressed primary tumor growth and tumor-associated vascularization in 4T1 tumors. Further, the DIM and CC combination exhibited a strong inhibitory effect on VEGF-induced angiogenesis in matrigel plugs. The mechanistic study demonstrated that DIM and CC could effectively downregulate VEGFA expression in tumor tissue and strongly interact with VEGFR2 to block its kinase activity. Interestingly, the DIM and CC combination also suppressed the lung metastasis of the highly metastatic 4T1 tumors through the downregulation of FAK/MMP9/2 signaling and reversal of epithelial-to-mesenchymal transition (EMT). Overall, these findings suggest that DIM-based nutraceuticals and functional foods can be developed as adjuvant therapy for treating TNBC.

Exploring the Role of Chemical Reactions in the Selectivity of Tyrosine Kinase Inhibitors

A variety of diseases are associated with tyrosine kinase enzymes that activate many proteins via signal transduction cascades. The similar ATP-binding pockets of these tyrosine kinases make it extremely difficult to design selective covalent inhibitors. The present study explores the contribution of the chemical reaction steps to the selectivity of the commercialized inhibitor acalabrutinib over the Bruton's tyrosine kinase (BTK) and the interleukin-2-inducible T-cell kinase (ITK). Ab initio and empirical valence bond (EVB) simulations of the two kinases indicate that the most favorable reaction path involves a water-assisted mechanism of the 2-butynamide reactive group of acalabrutinib. BTK reacts with acalabrutinib with a substantially lower barrier than ITK, according to our calculated free-energy profile and kinetic simulations. Such a difference is due to the microenvironment of the active site, as further supported by a sequence-based analysis of specificity determinants for several commercialized inhibitors. Our study involves a new approach of simulating directly the IC50 and inactivation efficiency k_eff, instead of using the standard formulas. This new strategy is particularly important in studies of covalent inhibitors with a very exothermic bonding step. Overall, our results demonstrate the importance of understanding the chemical reaction steps in designing selective covalent inhibitors for tyrosine kinases.

Intrinsically Fluorescent Anti-Cancer Drugs

At present, about one-third of the total protein targets in the pharmaceutical research sector are kinase-based. While kinases have been attractive targets to combat many diseases, including cancer, selective kinase inhibition has been challenging, because of the high degree of structural homology in the active site where many kinase inhibitors bind. Despite efficacy as cancer drugs, kinase inhibitors can exhibit limited target specificity and rationalizing their target profiles in the context of precise molecular mechanisms or rearrangements is a major challenge for the field. Spectroscopic approaches such as infrared, Raman, NMR and fluorescence have the potential to provide significant insights into drug-target and drug-non-target interactions because of sensitivity to molecular environment. This review places a spotlight on the significance of fluorescence for extracting information related to structural properties, discovery of hidden conformers in solution and in target-bound state, binding properties (e.g., location of binding sites, hydrogen-bonding, hydrophobicity), kinetics as well as dynamics of kinase inhibitors. It is concluded that the information gleaned from an understanding of the intrinsic fluorescence from these classes of drugs may aid in the development of future drugs with improved side-effects and less disease resistance.

Therapeutic potentials of genistein: New insights and perspectives

Genistein, a polyphenolic isoflavone compound found abundantly in soy or soy-based products, is widely consumed in the Asian population. Genistein has poor bioavailability, to overcome this problem many advanced nano-drug delivery carrier systems are designed to enhance its water solubility and stability. However, further research is required to develop more efficient bioavailability improvement strategies. Genistein is a phytoestrogen which has been associated with reducing the risk of cancer, cardiovascular disorders, and diabetes mellitus. This plant-based bioactive compound possesses numerous biological activities such as anti-oxidant, anti-inflammatory, anti-obesity, anti-cancer, cardioprotective, and anti-diabetic activities to treat various disease states. Genistein has been used as an active therapeutic agent in many medications. Moreover, several clinical trials are in the ongoing stage to develop more efficient treatment therapies, especially for cancer treatment. This article highlights the protective and therapeutic benefits of genistein in the treatment of different ailments, and more specifically elaborates on the anti-cancer potential of genistein regarding various types of cancers. PRACTICAL APPLICATIONS: Genistein possesses versatile biological activities, including anti-diabetic, anti-inflammatory, anti-oxidant, anti-obesity, and anti-angiogenic. The most studied activity is anti-cancer. Currently, a number of pre-clinical and clinical trials are being carried out on anti-neoplastic and cytotoxic activities of genistein to develop novel therapeutic agents with excellent anti-cancer potential for the treatment of various kinds of cancer. Moreover, many bioavailability enhancement strategies have been developed to improve the bioavailability of genistein. Genistein shows significant hypoglycemic effects alone or in combination with other anti-diabetic agents. Genistein in combination with other chemotherapeutic agents is used for the treatment of prostate, bone, colorectal, glioma, breast, and bladder cancer.

ST6Gal-I-mediated sialylation of the epidermal growth factor receptor modulates cell mechanics and enhances invasion

Heterogeneity within the glycocalyx influences cell adhesion mechanics and signaling. However, the role of specific glycosylation subtypes in influencing cell mechanics via alterations of receptor function remains unexplored. It has been shown that the addition of sialic acid to terminal glycans impacts growth, development, and cancer progression. In addition, the sialyltransferase ST6Gal-I promotes epidermal growth factor receptor (EGFR) activity, and we have shown EGFR is an 'allosteric mechano-organizer' of integrin tension. Here, we investigated the impact of ST6Gal-I on cell mechanics. Using DNA-based tension gauge tether probes of variable thresholds, we found that high ST6Gal-I activity promotes increased integrin forces and spreading in Cos-7 and OVCAR3, OVCAR5, and OV4 cancer cells. Further, employing inhibitors and function-blocking antibodies against β1, β3, and β5 integrins and ST6Gal-I targets EGFR, tumor necrosis factor receptor, and Fas cell surface death receptor, we validated that the observed phenotypes are EGFR-specific. We found that while tension, contractility, and adhesion are extracellular-signal-regulated kinase pathway-dependent, spreading, proliferation, and invasion are phosphoinositide 3-kinase-Akt serine/threonine kinase dependent. Using total internal reflection fluorescence microscopy and flow cytometry, we also show that high ST6Gal-I activity leads to sustained EGFR membrane retention, making it a key regulator of cell mechanics. Our findings suggest a novel sialylation-dependent mechanism orchestrating cellular mechanics and enhancing cell motility via EGFR signaling.

EGF-SNX3-EGFR axis drives tumor progression and metastasis in triple-negative breast cancers

Epidermal growth factor receptor (EGFR) has critical roles in epithelial cell physiology. Over-expression and over-activation of EGFR have been implicated in diverse cancers, including triple-negative breast cancers (TNBCs), prompting anti-EGFR therapies. Therefore, developing potent therapies and addressing the inevitable drug resistance mechanisms necessitates deciphering of EGFR related networks. Here, we describe Sorting Nexin 3 (SNX3), a member of the recycling retromer complex, as a critical player in the epidermal growth factor (EGF) stimulated EGFR network in TNBCs. We show that SNX3 is an immediate and sustained target of EGF stimulation initially at the protein level and later at the transcriptional level, causing increased SNX3 abundance. Using a proximity labeling approach, we observed increased interaction of SNX3 and EGFR upon EGF stimulation. We also detected colocalization of SNX3 with early endosomes and endocytosed EGF. Moreover, we show that EGFR protein levels are sensitive to SNX3 loss. Transient RNAi models of SNX3 downregulation have a temporary reduction in EGFR levels. In contrast, long-term silencing forces cells to recover and overexpress EGFR mRNA and protein, resulting in increased proliferation, colony formation, migration, invasion in TNBC cells, and increased tumor growth and metastasis in syngeneic models. Consistent with these results, low SNX3 and high EGFR mRNA levels correlate with poor relapse-free survival in breast cancer patients. Overall, our results suggest that SNX3 is a critical player in the EGFR network in TNBCs with implications for other cancers dependent on EGFR activity.

iPSC-endothelial cell phenotypic drug screening and in silico analyses identify tyrphostin-AG1296 for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disorder leading to occlusive vascular remodeling. Current PAH therapies improve quality of life but do not reverse structural abnormalities in the pulmonary vasculature. Here, we used high-throughput drug screening combined with in silico analyses of existing transcriptomic datasets to identify a promising lead compound to reverse PAH. Induced pluripotent stem cell-derived endothelial cells generated from six patients with PAH were exposed to 4500 compounds and assayed for improved cell survival after serum withdrawal using a chemiluminescent caspase assay. Subsequent validation of caspase activity and improved angiogenesis combined with data analyses using the Gene Expression Omnibus and Library of Integrated Network-Based Cellular Signatures databases revealed that the lead compound AG1296 was positively associated with an anti-PAH gene signature. AG1296 increased abundance of bone morphogenetic protein receptors, downstream signaling, and gene expression and suppressed PAH smooth muscle cell proliferation. AG1296 induced regression of PA neointimal lesions in lung organ culture and PA occlusive changes in the Sugen/hypoxia rat model and reduced right ventricular systolic pressure. Moreover, AG1296 improved vascular function and BMPR2 signaling and showed better correlation with the anti-PAH gene signature than other tyrosine kinase inhibitors. Specifically, AG1296 up-regulated small mothers against decapentaplegic (SMAD) 1/5 coactivators, cAMP response element-binding protein 3 (CREB3), and CREB5: CREB3 induced inhibitor of DNA binding 1 and downstream genes that improved vascular function. Thus, drug discovery for PAH can be accelerated by combining phenotypic screening with in silico analyses of publicly available datasets.

Targeting protein phosphatase PP2A for cancer therapy: development of allosteric pharmaceutical agents

Tumor initiation is driven by oncogenes that activate signaling networks for cell proliferation and survival involving protein phosphorylation. Protein kinases in these pathways have proven to be effective targets for pharmaceutical inhibitors that have progressed to the clinic to treat various cancers. Here, we offer a narrative about the development of small molecule modulators of the protein Ser/Thr phosphatase 2A (PP2A) to reduce the activation of cell proliferation and survival pathways. These novel drugs promote the assembly of select heterotrimeric forms of PP2A that act to limit cell proliferation. We discuss the potential for the near-term translation of this approach to the clinic for cancer and other human diseases.

Schwann cell precursors generate sympathoadrenal system during zebrafish development

The autonomic portion of the peripheral nervous system orchestrates tissue homeostasis through direct innervation of internal organs, and via release of adrenalin and noradrenalin into the blood flow. The developmental mechanisms behind the formation of autonomic neurons and chromaffin cells are not fully understood. Using genetic tracing, we discovered that a significant proportion of sympathetic neurons in zebrafish originates from Schwann cell precursors (SCPs) during a defined period of embryonic development. Moreover, SCPs give rise to the main portion of the chromaffin cells, as well as to a significant proportion of enteric and other autonomic neurons associated with internal organs. The conversion of SCPs into neuronal and chromaffin cells is ErbB receptor dependent, as the pharmacological inhibition of the ErbB pathway effectively perturbed this transition. Finally, using genetic ablations, we revealed that SCPs producing neurons and chromaffin cells migrate along spinal motor axons to reach appropriate target locations. This study reveals the evolutionary conservation of SCP-to-neuron and SCP-to-chromaffin cell transitions over significant growth periods in fish and highlights relevant cellular-genetic mechanisms. Based on this, we anticipate that multipotent SCPs might be present in postnatal vertebrate tissues, retaining the capacity to regenerate autonomic neurons and chromaffin cells.

Assessing the activation/inhibition of tyrosine kinase-related pathways with a newly developed platform

The phosphorylation of cellular proteins plays a crucial role in the transduction of various signals from outside the cell into the nucleus. The signals are transduced by phosphorylation chain reactions within multiple pathways; however, determining which pathways are responsible for each defined signal has proven challenging. To estimate the activity of each pathway, we developed a phosphorylation array platform comprising a protein array with 1200 proteins belonging to 376 signalling pathways and an analytical method to estimate pathway activity based on the phosphorylation levels of proteins. The performance of our system was assessed by reconstructing kinase-substrate relationships, as well as by estimating pathway activity upon epidermal growth factor (EGF) stimulation and the pharmacological inhibition of epidermal growth factor receptor (EGFR). As a result, kinase-substrate relationships were reliably reconstructed based on the precise measurement of phosphorylation levels of constituent proteins on the array. Furthermore, the pathway activities associated with EGF stimulation and EGFR inhibition were successfully traced through the related pathways from the outer membrane to the nucleus along a time course. Thus, our phosphorylation array system can effectively assess the activity of specific signalling pathways that are perturbed by extracellular stimuli, such as various drugs.

Discovery and Investigation of 1-[4-(2-Aminoethoxy)Phenylcarbonyl]- 3,5-Bis-(Benzylidene)-4-Piperidones as Candidate Antineoplastic Agents: Our Last 15 Years Study

This review outlines the discovery and development of a novel series of 1-[4-2- aminoethoxy)phenylcarbonyl]-3,5-bis-(benzylidene)-4-piperidones (5-8) as potential drug candidates over the last 15 years in our laboratory. Many of these compounds demonstrate excellent cytotoxic properties and are often more potent than contemporary anticancer drugs. Two highly important features of many of these molecules are first, the greater tumour-selective toxicity and second, the ability of these molecules to act as modulators of multi-drug resistance. The modes of action of some of the potent compounds are by apoptosis induction, generation of reactive oxygen species, activation of certain caspases and affecting mitochondrial functions. These molecules also display promising antimalarial and antimycobacterial properties. In a short term toxicity study, these molecules are well tolerated in mice. Structure-activity relationships and a drug delivery system along with pharmacokinetic studies and metabolic stability of these compounds, have been presented. The positive characteristics associated with the series (5-8) warrant their further evaluations as candidate antineoplastic drug candidates.

Discovery of Hyperstable Noncanonical Plant-Derived Epidermal Growth Factor Receptor Agonist and Analogs

Here, we report the discovery of the first plant-derived and noncanonical epidermal growth factor receptor (EGFR) agonist, the 36-residue bleogen pB1 from Pereskia bleo of the Cactaceae family. We show that bleogen pB1 is a low-affinity EGFR agonist using a suite of chemical, biochemical, cellular, and animal experiments which include incisor eruption and wound-healing mouse models. A focused positional scanning pB1 library of Ala- and d-amino acid scans yielded a high-affinity pB1 analog, [K29k]pB1, with a 60-fold-improved EGFR affinity and mitogenicity. We show that the potency of [K29k]pB1 and the epidermal growth factor (EGF) is comparable in a diabetic mouse wound-healing model. We also show that both bleogen pB1 and [K29k]pB1 are hyperstable, being >100-fold more stable than EGF against proteolytic degradation. Overall, our discovery of a noncanonical proteolytic-resistant EGFR agonist scaffold could open new avenues for developing wound healing and skin regeneration therapeutics and biomaterials.

Radiotherapy and Receptor Tyrosine Kinase Inhibition for Solid Cancers (ROCKIT): A Meta-Analysis of 13 Studies

Background

We hypothesized that the addition of receptor tyrosine kinase inhibitors (RTKis, e.g., lapatinib, erlotinib, cetuximab, bevacizumab, panitumumab) to radiotherapy-based treatment for solid tumors does not increase overall survival but may increase toxicity.

Methods

Population, Intervention, Control, Outcome, Study Design; Preferred Reporting Items for Systematic Reviews and Meta-Analyses; and Meta-analysis of Observational Studies in Epidemiology methods were used to identify prospective randomized studies including patients with solid tumor cancers treated with radiotherapy with or without RTKis. Extracted variables included use of radiotherapy vs chemoradiotherapy, RTKi type (antibody vs small molecule), outcomes, and toxicities. The primary endpoint was overall survival; the secondary endpoint was grade 3+ toxicity. Random-effects meta-analyses were performed for each outcome measure. All statistical tests were 2-sided.

Results

A total of 405 studies met the initial search criteria, of which 13 prospective randomized trials of radiotherapy with or without RTKi met the inclusion criteria, encompassing 5678 patients. The trials included cancers of the head and neck (6 trials, 3295 patients), esophagus (3 trials, 762 patients), lung (2 trials, 550 patients), and brain (2 trials, 1542 patients). Three studies evaluated a small molecule and radiotherapy in 949 patients, and 10 studies evaluated antibodies and radiotherapy in 4729 patients. The addition of RTKis to radiotherapy-based treatment did not improve overall survival (hazard ratio = 1.02, 95% confidence interval = 0.90 to 1.15, P = .76) but increased grade 3+ toxicity (relative risk = 1.18, 95% confidence interval = 1.06 to 1.33, P = .009).

Conclusions

The addition of RTKis to radiotherapy does not improve survival and worsens toxicity.

Nilotinib, A Tyrosine Kinase Inhibitor, Suppresses the Cell Growth and Triggers Autophagy in Papillary Thyroid Cancer

BACKGROUND

Papillary thyroid carcinoma (PTC) represents for the most common thyroid cancer. Until recently, treatment options for PTC patients are limited. Nilotinib is the second-generation tyrosine kinase inhibitor, and has been widely used in the treatment of chronic myeloid leukemia (CML).

OBJECTIVES

We aimed to explore whether nilotinib is effective in PTC cancer progression and the underlying mechanisms.

METHODS

In this study, the three human PTC cell lines (KTC-1, BCPAP, and TPC1) were used to verify the effects of nilotinib on cell growth. The half maximal inhibitory concentration (IC50) was calculated according to the growth curve post nilotinib treatment at different concentrations. Cell counting kit-8 and colony formation analysis were used to monitor cell growth after nilotinib treatment. Cell apoptosis and autophagy related proteins and phosphorylation of PI3K/Akt/mTOR were detected by Western blotting analysis.

RESULTS

Nilotinib treatment can effectively inhibit PTC cell growth, which was accompanied by increase of apoptosis and induction of autophagy. Mechanistically, nilotinib treatment repressed the phosphorylation of PI3K/Akt/mTOR pathway.

CONCLUSION

Collectively, our results demonstrated that nilotinib may display anti-tumor effect against PTC via inhibiting of PI3K/Akt/mTOR pathway and inducing apoptosis and autophagy.

Mechanical Stress Regulates Epithelial Tissue Integrity and Stiffness through the FGFR/Erk2 Signaling Pathway during Embryogenesis

Physical forces generated by tissue-tissue interactions are a critical component of embryogenesis, aiding the formation of organs in a coordinated manner. In this study, using Xenopus laevis embryos and phosphoproteome analyses, we uncover the rapid activation of the mitogen-activated protein (MAP) kinase Erk2 upon stimulation with centrifugal, compression, or stretching force. We demonstrate that Erk2 induces the remodeling of cytoskeletal proteins, including F-actin, an embryonic cadherin C-cadherin, and the tight junction protein ZO-1. We show these force-dependent changes to be prerequisites for the enhancement of cellular junctions and tissue stiffening during early embryogenesis. Furthermore, Erk2 activation is FGFR1 dependent while not requiring fibroblast growth factor (FGF) ligands, suggesting that cell/tissue deformation triggers receptor activation in the absence of ligands. These findings establish previously unrecognized functions for mechanical forces in embryogenesis and reveal its underlying force-induced signaling pathways.

Insights Into the Antiviral Pathways of the Silkworm Bombyx mori

The lepidopteran model silkworm, Bombyx mori, is an important economic insect. Viruses cause serious economic losses in sericulture; thus, the economic importance of these viruses heightens the need to understand the antiviral pathways of silkworm to develop antiviral strategies. Insect innate immunity pathways play a critical role in the outcome of infection. The RNA interference (RNAi), NF-kB-mediated, immune deficiency (Imd), and stimulator of interferon gene (STING) pathways, and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway are the major antiviral defense mechanisms, and these have been shown to play important roles in the antiviral immunity of silkworms. In contrast, viruses can modulate the prophenol oxidase (PPO), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), and the extracellular signal-regulated kinase (ERK) signaling pathways of the host to elevate their proliferation in silkworms. In this review, we present an overview of the current understanding of the main immune pathways in response to viruses and the signaling pathways modulated by viruses in silkworms. Elucidation of these pathways involved in the antiviral mechanism of silkworms furnishes a theoretical basis for the enhancement of virus resistance in economic insects, such as upregulating antiviral immune pathways through transgenic overexpression, RNAi of virus genes, and targeting these virus-modulated pathways by gene editing or inhibitors.

TNF-α-induced sympathetic excitation requires EGFR and ERK1/2 signaling in cardiovascular regulatory regions of the forebrain

Peripherally or centrally administered TNF-α elicits a prolonged sympathetically mediated pressor response, but the underlying molecular mechanisms are unknown. Activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in cardiovascular regions of the brain has recently been recognized as a key mediator of sympathetic excitation, and ERK1/2 signaling is induced by activation of epidermal growth factor receptor (EGFR) tyrosine kinase activity. The present study examined the role of EGFR and ERK1/2 signaling in the sympathetic response to TNF-α. In urethane-anesthetized rats, intracarotid artery injection of TNF-α increased phosphorylation of EGFR and ERK1/2 in the subfornical organ (SFO) and the hypothalamic paraventricular nucleus (PVN); upregulated the gene expression of excitatory mediators in SFO and PVN; and increased blood pressure (BP), heart rate (HR), and renal sympathetic nerve activity (RSNA). A continuous intracerebroventricular infusion of the selective EGFR tyrosine kinase inhibitor AG1478 or the ERK1/2 inhibitor PD98059 significantly attenuated these responses. Bilateral PVN microinjections of TNF-α also increased phosphorylated ERK1/2 and the gene expression of excitatory mediators in PVN, along with increases in BP, HR, and RSNA, and these responses were substantially reduced by prior bilateral PVN microinjections of AG1478. These results identify activation of EGFR in cardiovascular regulatory regions of the forebrain as an important molecular mediator of TNF-α-driven sympatho-excitatory responses and suggest that EGFR activation of the ERK1/2 signaling pathway plays an essential role. These mechanisms likely contribute to sympathetic excitation in pathophysiological states like heart failure and hypertension, in which circulating and brain TNF-α levels are increased.NEW & NOTEWORTHY Proinflammatory cytokines contribute to the augmented sympathetic nerve activity in hypertension and heart failure, but the central mechanisms involved are largely unknown. The present study reveals that TNF-α transactivates EGFR in the subfornical organ and the hypothalamic paraventricular nucleus to initiate ERK1/2 signaling, upregulate the gene expression of excitatory mediators, and increase sympathetic nerve activity. These findings identify EGFR as a gateway to sympathetic excitation and a potential target for intervention in cardiovascular disease states.

Epidermal growth factor receptor activity upregulates lactate dehydrogenase A expression, lactate dehydrogenase activity, and lactate secretion in cultured IB3-1 cystic fibrosis lung epithelial cells

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. It has been postulated that reduced HCO₃^- transport through CFTR may lead to a decreased airway surface liquid pH. In contrast, others have reported no changes in the extracellular pH (pHe). We have recently reported that in carcinoma Caco-2/pRS26 cells (transfected with short hairpin RNA for CFTR) or CF lung epithelial IB3-1 cells, the mutation in CFTR decreased mitochondrial complex I activity and increased lactic acid production, owing to an autocrine IL-1β loop. The secreted lactate accounted for the reduced pHe, because oxamate fully restored the pHe. These effects were attributed to the IL-1β autocrine loop and the downstream signaling kinases c-Src and JNK. Here we show that the pHe of IB3-1 cells can be restored to normal values (∼7.4) by incubation with the epidermal growth factor receptor (EGFR, HER1, ErbB1) inhibitors AG1478 and PD168393. PD168393 fully restored the pHe values of IB3-1 cells, suggesting that the reduced pHe is mainly due to increased EGFR activity and lactate. Also, in IB3-1 cells, lactate dehydrogenase A mRNA, protein expression, and activity are downregulated when EGFR is inhibited. Thus, a constitutive EGFR activation seems to be responsible for the reduced pHe in IB3-1 cells.

Advances in Synthesis, Derivatization and Bioactivity of Isatin: A Review

Background:

Isatin (IST) is a crucial pharmacologically active compound, chemically known as indole- 1H-2,3-dione. Development of different IST based analogues acquired significant awareness because of its pronounced therapeutic importance such as analgesic, anticancer, anti-inflammatory, antitubercular, antimicrobial, antifungal, antiviral (effective against SARS coronavirus 3C protease) and many other activities, and represents an important class of heterocyclic compounds that can be used as a precursor for the synthesis of many useful drugs.

Objective:

Previously, many articles were reported on IST synthesis and its different pharmacological activities but herein, we mentioned 59 different synthesis schemes of several IST derivatives/hybrids derived from the substitution of the nitrogen, aromatic ring, the second and third position of IST along with most potent molecule among each of synthesized libraries with their structural activity relationship (SAR). Using these standardized approaches, several biologically important compounds were developed like sunitinib, nintedanib, indirubin, etc and several studies have been carried out nowadays to develop newer compounds having fewer side effects and also overcome the problem of resistance.

Conclusion:

This report critically reviews the different strategies for the designs and synthesis of several IST based compounds having different biological activities with SAR, which can favour further investigation and modification for the development of new and more potent entities.

External and internal EGFR-activating signals drive mammary epithelial cells proliferation and viability

During puberty, the mammary gland undergoes an intense growth, dependent on the interplay between the Epidermal Growth Factor Receptor (EGFR) in the stroma and different mammary epithelial receptors. We hypothesize that EGFR expressed in the mammary epithelium also has a role in puberty and the epithelial cells can self-sustain by EGFR-mediated autocrine signaling. We adopted mammary cell lines from different species, as in vitro model for the epithelium, and we observed that EGFR-signaling positively affects their survival and proliferation. Once deprived of external growth factors, mammary cells still showed strong Erk 1/2 phosphorylation, abolished upon EGFR inhibition, coupled with a further reduction in survival and proliferation. Based on gene expression analysis, three EGFR-ligands (AREG, EREG and HBEGF) are likely to mediate this autocrine signaling. In conclusion, internal EGFR-activating signals sustain mammary epithelial cell proliferation and survival in vitro.

Review on Epidermal Growth Factor Receptor (EGFR) Structure, Signaling Pathways, Interactions, and Recent Updates of EGFR Inhibitors

The epidermal growth factor receptor (EGFR) belongs to the ERBB family of tyrosine kinase receptors. EGFR signaling cascade is a key regulator in cell proliferation, differentiation, division, survival, and cancer development. In this review, the EGFR structure and its mutations, signaling pathway, ligand binding and EGFR dimerization, EGF/EGFR interaction, and the progress in the development of EGFR inhibitors have been explored.

Development of Radiogallium-Labeled Peptides for Platelet-Derived Growth Factor Receptor β (PDGFRβ) Imaging: Influence of Different Linkers

The purpose of this study is to develop peptide-based platelet-derived growth factor receptor β (PDGFRβ) imaging probes and examine the effects of several linkers, namely un-natural amino acids (D-alanine and β-alanine) and ethylene-glycol (EG), on the properties of Ga-DOTA-(linker)-IPLPPPRRPFFK peptides. Seven radiotracers, ⁶⁷Ga-DOTA-(linker)-IPLPPPRRPFFK peptides, were designed, synthesized, and evaluated. The stability and cell uptake in PDGFRβ positive peptide cells were evaluated in vitro. The biodistribution of [⁶⁷Ga]Ga-DOTA-EG₂-IPLPPPRRPFFK ([⁶⁷Ga]27) and [⁶⁷Ga]Ga-DOTA-EG₄-IPLPPPRRPFFK ([⁶⁷Ga]28), which were selected based on in vitro stability in murine plasma and cell uptake rates, were determined in BxPC3-luc-bearing nu/nu mice. Seven ⁶⁷Ga-labeled peptides were successfully synthesized with high radiochemical yields (>85%) and purities (>99%). All evaluated radiotracers were stable in PBS (pH 7.4) at 37 °C. However, only [⁶⁷Ga]27 and [⁶⁷Ga]28 remained more than 75% after incubation in murine plasma at 37 °C for 1 h. [⁶⁷Ga]27 exhibited the highest BxPC3-luc cell uptake among the prepared radiolabeled peptides. As regards the results of the biodistribution experiments, the tumor-to-blood ratios of [⁶⁷Ga]27 and [⁶⁷Ga]28 at 1 h post-injection were 2.61 ± 0.75 and 2.05 ± 0.77, respectively. Co-injection of [⁶⁷Ga]27 and an excess amount of IPLPPPRRPFFK peptide as a blocking agent can significantly decrease this ratio. However, tumor accumulation was not considered sufficient. Therefore, further probe modification is required to assess tumor accumulation for in vivo imaging.

A mouse model reveals the events and underlying regulatory signals during the gonadotrophin-dependent phase of follicle development

During folliculogenesis, the gonadotrophin (GTH)-dependent phase begins at the small antral follicle stage and ends with Graafian follicles. In this study, pregnant mare's serum GTH was used to induce GTH-dependent folliculogenesis in mice, following which the developmental events that follicles undergo, as well as the underlying regulatory signals, were investigated at both the morphological and transcriptomic level. GTH-dependent folliculogenesis consisted of three phases: preparation, rapid growth and decelerated growth. In the preparation phase, comprising the first 12 h, granulosa cells completed the preparations for proliferation and differentiation, shifted energy metabolism to glycolysis, and reduced protein synthesis and processing. The rapid growth phase lasted from 12 to 24 h; in this phase, granulosa cells completed their proliferation, and follicles acquired the capacity for estradiol secretion and ovulation. Meanwhile, the decelerating growth phase occurred between 24 and 48 h of GTH-dependent folliculogenesis. In this phase, the proliferation and expansion of the follicular antrum were reduced, energy metabolism was shifted to oxidative phosphorylation, and cell migration and lipid metabolism were enhanced in preparation for luteinization. We also revealed the key signaling pathways that regulate GTH-dependent folliculogenesis and elucidated the activation sequence of these pathways. A comparison of our RNA-sequencing data with that reported for humans suggested that the mechanisms involved in mouse and human folliculogenesis are evolutionarily conserved. In this study, we draw a detailed atlas of GTH-dependent folliculogenesis, thereby laying the foundation for further investigation of the regulatory mechanisms underlying this process.

Normal vitreous promotes angiogenesi via the epidermal growth factor receptor

Vitreous, a transparent tissue in our body, contains anti-angiogenesis factors. Our previous work reported that vitreous activates the signaling pathway of epidermal growth factor receptor (EGFR), which plays a critical role in angiogenesis. The aim of this study was to determine the role of EGFR in vitreous-induced angiogenesis-related cellular responses in vitro. Using a pharmacologic and molecular approach, we found that vitreous increased proliferation and migration via EGFR in human umbilical vein endothelial cells (HUVECs). Furthermore, we demonstrated that vitreous promoted tube formation via EGFR in HUVECs. Subsequently, depletion of EGFR using CRISPR/Cas9 and blockage with EGFR inhibitor AG1478 suppressed vitreous-induced Akt activation and cell proliferation, migration, and tube formation in HUVECs. The significance of the angiogenic effect derived from vitreous demonstrates the importance of vitreous in the ocular physiology and the pathobiology of angiogenesis-related ophthalmic diseases, such as proliferative diabetic retinopathy.

Hepatocyte Growth Factor and Macrophage-stimulating Protein "Hinge" Analogs to Treat Pancreatic Cancer

Pancreatic cancer (PC) ranks twelfth in frequency of diagnosis but is the fourth leading cause of cancer related deaths with a 5 year survival rate of less than 7 percent. This poor prognosis occurs because the early stages of PC are often asymptomatic. Over-expression of several growth factors, most notably vascular endothelial growth factor (VEGF), has been implicated in PC resulting in dysfunctional signal transduction pathways and the facilitation of tumor growth, invasion and metastasis. Hepatocyte growth factor (HGF) acts via the Met receptor and has also received research attention with ongoing efforts to develop treatments to block the Met receptor and its signal transduction pathways. Macrophage-stimulating protein (MSP), and its receptor Ron, is also recognized as important in the etiology of PC but is less well studied. Although the angiotensin II (AngII)/AT1 receptor system is best known for mediating blood pressure and body water/electrolyte balance, it also facilitates tumor vascularization and growth by stimulating the expression of VEGF. A metabolite of AngII, angiotensin IV (AngIV) has sequence homology with the "hinge regions" of HGF and MSP, key structures in the growth factor dimerization processes necessary for Met and Ron receptor activation. We have developed AngIV-based analogs designed to block dimerization of HGF and MSP and thus receptor activation. Norleual has shown promise as tested utilizing PC cell cultures. Results indicate that cell migration, invasion, and pro-survival functions were suppressed by this analog and tumor growth was significantly inhibited in an orthotopic PC mouse model.

Lysophosphatidic acid induces tumor necrosis factor-alpha to regulate a pro-inflammatory cytokine network in ovarian cancer

Epithelial ovarian carcinoma tissues express high levels of tumor necrosis factor-alpha (TNF-α) and other inflammatory cytokines. The underlying mechanism leading to the abnormal TNF-α expression in ovarian cancer remains poorly understood. In the current study, we demonstrated that lysophosphatidic acid (LPA), a lipid mediator present in ascites of ovarian cancer patients, induced expression of TNF-α mRNA and release of TNF-α protein in ovarian cancer cells. LPA also induced expression of interleukin-1β (IL-1β) mRNA but no significant increase in IL-1β protein was detected. LPA enhanced TNF-α mRNA through NF-κB-mediated transcriptional activation. Inactivation of ADAM17, a disintegrin and metalloproteinase, with a specific inhibitor TMI-1 or by shRNA knockdown prevented ovarian cancer cells from releasing TNF-α protein in response to LPA, indicating that LPA-mediated TNF-α production relies on both transcriptional upregulations of the TNF-α gene and the activity of ADAM17, the membrane-associated TNF-α-converting enzyme. Like many other biological responses to LPA, induction of TNF-α by LPA also depended on the transactivation of the epidermal growth factor receptor (EGFR). Interestingly, our results revealed that ADAM17 was also the shedding protease responsible for the transactivation of EGFR by LPA in ovarian cancer cells. To explore the biological outcomes of LPA-induced TNF-α, we examined the effects of a TNF-α neutralizing antibody and recombinant TNF-α soluble receptor on LPA-stimulated expression of pro-tumorigenic cytokines and chemokines overexpressed in ovarian cancer. Blockade of TNF-α signaling significantly reduced the production of IL-8, IL-6, and CXCL1, suggesting a hierarchy of mechanisms contributing to the robust expression of the inflammatory mediators in response to LPA in ovarian cancer cells. In contrast, TNF-α inhibition did not affect LPA-dependent cell proliferation. Taken together, our results establish that the bioactive lipid LPA drives the expression of TNF-α to regulate an inflammatory network in ovarian cancer.

Schwann cells selectively myelinate primary motor axons via neuregulin-ErbB signaling

Spinal motor neurons project their axons out of the spinal cord via the motor exit point (MEP) and regulate their target muscle fibers for diverse behaviors. Several populations of glial cells including Schwann cells, MEP glia, and perineurial glia are tightly associated with spinal motor axons in nerve fascicles. Zebrafish have two types of spinal motor neurons, primary motor neurons (PMNs) and secondary motor neurons (SMNs). PMNs are implicated in the rapid response, whereas SMNs are implicated in normal and slow movements. However, the precise mechanisms mediating the distinct functions of PMNs and SMNs in zebrafish are unclear. In this study, we found that PMNs were myelinated by MEP glia and Schwann cells, whereas SMNs remained unmyelinated at the examined stages. Immunohistochemical analysis revealed that myelinated PMNs solely innervated fast muscle through a distributed neuromuscular junction (NMJ), whereas unmyelinated SMNs innervated both fast and slow muscle through distributed and myoseptal NMJs, respectively, indicating that myelinated PMNs could provide rapid responses for startle and escape movements, while unmyelinated SMNs regulated normal, slow movement. Further, we demonstrate that neuregulin 1 (Nrg1) type III-ErbB signaling provides a key instructive signal that determines the myelination of primary motor axons by MEP glia and Schwann cells. Perineurial glia ensheathed unmyelinated secondary motor axons and myelinated primary motor nerves. Ensheathment required interaction with both MEP glia and Schwann cells. Collectively, these data suggest that primary and secondary motor neurons contribute to the regulation of movement in zebrafish with distinct patterns of myelination.

Regulation of Hippo-YAP signaling by insulin-like growth factor-1 receptor in the tumorigenesis of diffuse large B-cell lymphoma

Background

Hippo-Yes-associated protein (YAP) signaling is a key regulator of organ size and tumorigenesis, yet the underlying molecular mechanism is still poorly understood. At present, the significance of the Hippo-YAP pathway in diffuse large B-cell lymphoma (DLBCL) is ill-defined.

Methods

The expression of YAP in DLBCL was determined in public database and clinical specimens. The effects of YAP knockdown, CRISPR/Cas9-mediated YAP deletion, and YAP inhibitor treatment on cell proliferation and the cell cycle were evaluated both in vitro and in vivo. RNA sequencing was conducted to detect dysregulated RNAs in YAP-knockout DLBCL cells. The regulatory effects of insulin-like growth factor-1 receptor (IGF-1R) on Hippo-YAP signaling were explored by targeted inhibition and rescue experiments.

Results

High expression of YAP was significantly correlated with disease progression and poor prognosis. Knockdown of YAP expression suppressed cell proliferation and induced cell cycle arrest in DLBCL cells. Verteporfin (VP), a benzoporphyrin derivative, exerted an anti-tumor effect by regulating the expression of YAP and the downstream target genes, CTGF and CYR61. In vitro and in vivo studies revealed that deletion of YAP expression with a CRISPR/Cas9 genome editing system significantly restrained tumor growth. Moreover, downregulation of IGF-1R expression led to a remarkable decrease in YAP expression. In contrast, exposure to IGF-1 promoted YAP expression and reversed the inhibition of YAP expression induced by IGF-1R inhibitors.

Conclusions

Our study highlights the critical role of YAP in the pathogenesis of DLBCL and uncovers the regulatory effect of IGF-1R on Hippo-YAP signaling, suggesting a novel therapeutic strategy for DLBCL.

Schistosoma mansoni FES Tyrosine Kinase Involvement in the Mammalian Schistosomiasis Outcome and Miracidia Infection Capability in Biomphalaria glabrata

Schistosomiasis is a neglected tropical disease (NTD) caused by helminthes from the Schistosoma genus. This NTD can cause systemic symptoms induced by the deposition of parasite eggs in the host liver, promoting severe complications. Functional studies to increase knowledge about parasite biology are required for the identification of new drug targets, because the treatment is solely based on praziquantel administration, a drug in which the mechanism of action is still unknown. Protein kinases are important for cellular adaptation and maintenance of many organisms homeostasis and, thus, are considered good drug targets for many pathologies. Accordingly, those proteins are also important for Schistosoma mansoni, as the parasite relies on specific environmental signals to develop into its different stages. However, the specific roles of protein kinases in S. mansoni biology are not well understood. This work aims at investigating the tyrosine-protein kinase FES (Feline Sarcoma) functions in the maintenance of S. mansoni life cycle, especially in the establishment of mammalian and invertebrate hosts' infection. In this regard, the verification of Smfes expression among S. mansoni stages showed that Smfes is more expressed in infective free-living stages: miracidia and cercariae. Schistosomula exposed to SmFES-dsRNA in vitro presented a reduction in movement and size and increased mortality. Mice infected with Smfes-knocked-down schistosomula exhibited a striking reduction in the area of liver granuloma and an increased rate of immature eggs in the intestine. Female adult worms recovered from mice presented a reduced size and changes in the ovary and vitellarium; and males exhibited damage in the gynecophoral canal. Subsequently, miracidia hatched from eggs exposed to SmFES-dsRNA presented changes in its capability to infect and to sense the snail mucus. In addition, the SmFES RNAi effect was stable from miracidia to cercariae. The establishment of infection with those cercariae reproduced the same alterations observed for the knocked-down schistosomula infection. Our findings show that SmFES tyrosine kinase (1) is important in schistosomula development and survival; (2) has a role in adult worms pairing and, consequently, female maturation; (3) might be essential for egg antigen expression, thus responsible for inducing granuloma formation and immunomodulation; and (4) is essential for miracidia infection capability. In addition, this is the first time that a gene is kept knocked down during three different S. mansoni life stages and that a tyrosine kinase is implicated in the parasite reproduction and infection establishment in the mammalian host. Accordingly, SmFES should be explored as an alternative to support schistosomiasis treatment and morbidity control.